Nuclear power currently provides around 20% of the world's electricity, with France obtaining about 80% of its power from nuclear energy. The U.S. began developing civilian nuclear programs after World War 2 and the first nuclear reactor to produce usable electricity was the Experimental Breeder Reactor-1 in Idaho in 1951. However, growth in nuclear power stalled after accidents like Three Mile Island raised public safety concerns. Major challenges facing expanded nuclear power are cost, safety, nuclear proliferation, and long-term waste storage.